THE MICROSCOPE. 



one will be thin enough. Float this little section on the glass slide 

 with a camel's hair brush. Holding the little piece in its place on 

 the slide with a needle — the needle should have been wedged into a 

 wooden handle for convenience — wash the specimen in water many 

 times with the camel's hair brush, so as to remove as much as 

 possible of the starch. The longitudinal section should be prepared 

 in the same way. In cutting the longitudinal section care should 

 be taken to cut near the center, so as to have some of the woody 

 cord in the specimen. After these sections have been thoroughly 

 examined under the microscope, the powdered ipecac can be 

 studied. A drop of water is placed on the glass slide by means of 

 the camel's hair brush and just a little of the powder taken on the 

 point of the penknife and dusted over the water — only a small amount 



FIG. 3. Potato Starch, x 375. 



of the powder is to be taken. After protecting it with the thin 

 glass-cover it is ready to be examined. Any one who has taken 

 these steps, can test for themselves the purity of the powdered 

 ipecac found in the drug stores. 



The following substances are reported as having been found in 

 powdered ipecacuanha: almond meal, licorice, corn meal and 

 potato starch. 



The presence of almond meal can be detected by the develop- 

 ment of hydrocyanic acid upon infusion in water. The presence of 

 the seed coats as well as the central part of the almond may be de- 

 tected by the microscope. The central part or the cotyledons are 

 composed of thin walled hexagonal cells, smaller than the cells of 



